Always on headwear recording system

ABSTRACT

A system that records audio and stores the recording is provided. The system includes first and second monitoring assemblies mounted in an earpiece that occludes and forms an acoustic seal of an ear canal. The first monitoring assembly includes an ambient sound microphone (ASM) to monitor an ambient acoustic field and produce an ASM signal. The second monitoring assembly includes an ear canal microphone (ECM) to monitor an acoustic field within the ear canal and produce an ECM signal. The system also includes a data storage device configured to act as a circular buffer for continually storing at least one of the ECM signal or the ASM signal, a further data storage device and a record-activation system. The record-activation system activates the further data storage device to record a content of the data storage device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. Ser. No.13/352,694, filed Jan. 18, 2012, which is a continuation application ofU.S. Ser. No. 12/100,281, filed Apr. 9, 2008 which claims the benefit ofU.S. provisional patent application No. 60/910,808 filed 9 Apr. 2007.The disclosure of which is incorporated herein by reference in itsentirety.

FIELD OF THE INVENTION

The present invention relates to earpieces, in particular, though notexclusively, the present invention relates to recording audio for aparticular time span while the earpiece is in use.

BACKGROUND OF THE INVENTION

The combination of the recent increase in Personal Media Players (PMPs)and rises in urban noise levels have all contributed to the ubiquity ofin-ear-canal (or insert) earphones. Such insert headphones afford theuser of 20-35 dB of passive noise attenuation, thereby allowing anincrease signal-to-noise ratio for reproduced Audio Content (e.g. musicfrom a PMP). This is advantageous for loud-noise work environments; suchas medical operating rooms where sound pressure levels can reach inexcess of 120 dB (Kracht et al, 2006). The assembly housing theearphones in the left and right ear of the user is, furthermore, ideallysituated to house a number of microphones to facilitate binauralrecording of the user's sound exposure.

U.S. Pat. No. 6,728,385 describes a system that uses the assemblydescribed in U.S. Pat. No. 7,039,195 to detect user-created voice bycomparing the signal level of the ECM and ASM's in one earphone deviceto operate a VOX automatic “push-to-talk” switch. U.S. Pat. No.7,039,195 also describes for in-situ estimation of the overviewattenuation provided by the earpiece (i.e. a NRR).

U.S. Pat. No. 6,661,901 describes a system that uses the assemblydescribed in U.S. Pat. No. 7,039,195 and a signal processing circuitryto transform the ECM signal into a signal which sounds natural to theuser after processing and auditioning with the ECR.

A fall monitoring device is described in U.S. Pat. No. 6,433,690comprising an accelerometer to detect whether the user's body is at anangle indicative of a fall. U.S. Pat. No. 6,647,368 also describes amethod for detecting changes in head location using a pair ofmicrophones to detect air pressure changes within and external to anoccluded ear canal.

SUMMARY OF THE INVENTION

At least one exemplary embodiment is directed to a device (e.g.,earpiece) that can record acoustic signals measured by microphones inthe device.

At least one exemplary embodiment is directed to An Always-On RecordingSystem (AORS) comprising: an acoustic monitoring assembly configured tomonitor the acoustic field in a user's immediate environment using anAmbient Sound Microphone (ASM) to monitor sound at an occluded earcanal; a signal processing circuit operatively connected to theassembly, where the signal processing circuit is configured to amplifyan ASM signal from the ASM and to equalize for the frequency sensitivityof the ASM; an acoustic field monitoring assembly configured to monitorthe acoustic field in the occluded ear canal, comprising an ear canalmicrophone (ECM) mounted in an earpiece that forms an acoustic seal ofthe occluded ear canal; a signal processing circuit configured toamplify an ECM signal from the ECM and to equalize for the frequencysensitivity of the ECM; and a data storage device configured to act as acircular buffer for constantly storing at least one of the ECM signaland the ASM signal.

Further areas of applicability of exemplary embodiments of the presentinvention will become apparent from the detailed description providedhereinafter. It should be understood that the detailed description andspecific examples, while indicating exemplary embodiments of theinvention, are intended for purposes of illustration only and are notintended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of present invention will become more fullyunderstood from the detailed description and the accompanying drawings,wherein:

FIG. 1A is an illustration of a general earpiece configuration accordingto at least one exemplary embodiment;

FIG. 1B is an illustration of a general configuration of a device (e.g.,earpiece) in accordance with at least one exemplary embodiment;

FIG. 1C is an illustration of a general configuration of a device (e.g.,earpiece) in accordance with at least one exemplary embodiment;

FIG. 2A is a general configuration of a device according to at least oneexemplary embodiment;

FIG. 2B is a general configuration of a device according to at least oneexemplary embodiment;

FIG. 3A is a general configuration of a device including an Always onRecording System according to at least one exemplary embodiment;

FIG. 3B illustrates a flow chart of processes in accordance with atleast one exemplary embodiment;

FIG. 3C illustrates a flow chart of processes in accordance with atleast one exemplary embodiment;

FIG. 3D illustrates a flow chart of processes in accordance with atleast one exemplary embodiment; and

FIG. 3E illustrates a flow chart of processes in accordance with atleast one exemplary embodiment.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE PRESENT INVENTION

The following description of exemplary embodiment(s) is merelyillustrative in nature and is in no way intended to limit the invention,its application, or uses.

Exemplary embodiments are directed to or can be operatively used onvarious wired or wireless earpieces devices (e.g., earbuds, headphones,ear terminal, behind the ear devices or other acoustic devices as knownby one of ordinary skill, and equivalents).

Processes, techniques, apparatus, and materials as known by one ofordinary skill in the art may not be discussed in detail but areintended to be part of the enabling description where appropriate. Forexample specific computer code may not be listed for achieving each ofthe steps discussed, however one of ordinary skill would be able,without undo experimentation, to write such code given the enablingdisclosure herein. Such code is intended to fall within the scope of atleast one exemplary embodiment.

Additionally exemplary embodiments are not limited to earpieces, forexample some functionality can be implemented on other systems withspeakers and/or microphones for example computer systems, PDAs,BlackBerry smart phones, cell and mobile phones, and any other devicethat emits or measures acoustic energy. Additionally, exemplaryembodiments can be used with digital and non-digital acoustic systems.Additionally various receivers and microphones can be used, for exampleMEMs transducers, diaphragm transducers, for example Knowles' FG and EGseries transducers.

Notice that similar reference numerals and letters refer to similaritems in the following figures, and thus once an item is defined in onefigure, it may not be discussed or further defined in the followingfigures.

The AORS records audio information and can obtain information from atleast one acoustic sound sensor(s) (microphones) mounted in theear-sealing assembly. The ear-sealing assembly can provide a NoiseReduction Rating of 20-30 dB. In at least one exemplary embodiment ofthe present invention a number of microphones are located outside theoccluded ear canal to monitor sound pressure levels near the entrance tothe ear canal (this is the Ambient Sound Microphone-ASM) and within theoccluded ear canal to facilitate monitoring of sound within the earcanal (this is the Ear Canal Microphone-ECM). The signal generated bythe ASM allows for a binaural recording of the user's recent soundexposure for purposes such as automatic dictation and transmission to abinaural audio signal recording and/or monitoring system. In addition,the signal generated by the Ear Canal Receiver (ECR) may be recorded toanalyze the performance of the signal processing assembly within theearphone. Thirdly, the signal generated by the ECM may be recorded toanalyze and predict the sound stimulus the user's ear drum is exposedto.

The AORS user can audition a recent sound exposure history in theabsence of a second signal processing device by recalling data stored ina circular buffer of computer data memory located within the earphonestructural assembly. U.S. Pat. No. 5,887,070 describes an insertearphone for reproducing audio content (e.g. audio from a Personal MediaPlayer or cell phone) to a user, but differs from at least one exemplaryembodiment of the present invention by at least not including any soundsensors or a device to record the user's local sound field. Theparticular sound sensors in at least one exemplary embodiment of thepresent invention can be mounted at the entrance to the occluded earcanal, and these microphones are called the Ambient Sound Microphones(ASMs). By recording the output of the left and right ASMs, a binauralrecording is therefore obtained.

U.S. Pat. No. RE38351 describes an insert earphone for the reproductionof audio content using a receiver mounted in a soft foam assembly thatforms a seal in the same ear canal. The AORS disclosed in at least oneexemplary embodiment of the present invention differs from U.S. Pat. No.RE38351 with at least the inclusion of a number of microphones mountedin each left and right earphone.

U.S. Pat. No. 5,946,050 discusses a system for monitoring a broadcastaudio signal for particular verbal messages (“keywords”) that activatean audio recording system to record the broadcasted signal. U.S. Pat.No. 5,946,050 uses a circular audio buffer for the input audio signal,so therefore the audio information slightly before the keyword occurscan also be recorded, which is useful for giving a context of the audiobefore the keyword occurs. In at least one exemplary embodiment of thepresent invention AORS differs from such automatic recording devices asU.S. Pat. No. 5,946,050 by specifically using binaural microphone outputsignals as the recorded data and also facilitates a recording to beactivated by a manual user operation, such as by pressing a button onthe earphone device, or automatically, in response to a particularnon-speech acoustic stimulus (which shall be described later).

In addition to the ASMs, the output of one or more acoustic sensorswithin the occluded ear canal of the AORS user is recorded. This ismeasured using an Ear Canal Microphone (ECM), which is acousticallyisolated from ambient sound (i.e. sound in the user's immediateenvironment, outside of the ear canal). Taken in combination with theASM signal, this facilitates recording of both the ambient soundexposure of the user and the actual sound exposure that the userperceives (or at least, the sound which the user's ear drum isstimulated with). The signal reproduced by the Ear Canal Receiver canalso be recorded. The electronic signal generated by the ASMs can beused to create a Binaural Recording, maintaining the unique Head RelatedTransfer Function of the user when the recording is replayed usingearphones.

U.S. Pat. No. 7,039,195 describes an ear terminal device with thefollowing features: an ear plug forming a seal in the user's meatus, inwhich is housed: an ambient sound microphone to monitor sound outsidethe user's meatus; an ear canal receiver to reproduce a mix of sounddetected by the ASM and also audio content e.g. from a remote user viaradio; an ear canal microphone to detect sound in the blocked ear canalof the user. U.S. Pat. No. 7,039,195 includes an electronics circuit forundertaking active noise cancellation using the ASM and ECR signal. Atleast one exemplary embodiment of the present invention differs fromU.S. Pat. No. 7,039,195 in a number of ways. For example, the ASM in atleast one exemplary embodiment is recessed in the meatus, and monitorssound which has been modified by transmission through a diaphragm thatmodifies the sound in a number of ways, for example one such way is thatthe diaphragm is tuned to resonate in such a way as to compensate forspectral sensitivity of the ASM. Another way is that the diaphragmundertakes beam-forming using holes located at particular locations inthe diaphragm, this allows the spatial sensitivity of the signaldetected by the ASM to be altered; e.g. increasing sensitivity in thedirection of the user's head direction.

U.S. Pat. No. 6,567,524 describes a system that uses the assemblydescribed in U.S. Pat. No. 7,039,195 and a signal processing circuitryto determine if the ear plug is correctly fitted by reproducing apredefined test signal with the ECR and measuring the response with theECM and comparing this new measured response to a stored measuredresponse. Again, the present invention does not describe a method orobject related to this intended function of U.S. Pat. No. 6,661,901.

U.S. Pat. No. 4,088,849 discloses a binaural recording system, utilizingan ambient sound microphone on the external body of a circum-auralheadphone. This does not provide a true binaural recording, as themicrophone sensors are not mounted at the entrance to the ear canal.

U.S. Pat. No. 4,819,270 is a binaural recording system comprising a pairof small, visually unobtrusive microphones intended to be mounted nearthe user's ear, but outside of the pinna (e.g. mounted on the earsupport of common eyewear). Again, this system does not provide a truebinaural recording, as the microphone sensor is not coincident with theuser's ear canal opening (i.e. ear meatus).

U.S. Pat. No. 2006/0182287 describes an earphone monitoring system, withmicrophones mounted at the entrance to an occluded ear canal (i.e.ASMs), and ear-canal receivers mounted in the same earphone. The presentinvention differs from U.S. Pat. No. 2006/0182287 with the addition of asound recording system to permit binaural recordings of the ASM, and arecording activation system to automatically or manually start and stopthe recording in response to either a user action or a specific event inthe user's local environment.

The archival recording functionality provided by the AORS is activatedin a number of ways. Besides a manual user-invoked recording, therecording may be initiated automatically in response to an accident inthe physical locality of the user, detected by the AORS with themicrophones within the earphone assembly.

Archival recording may also be initiated in response to particularsound. The Transient Event Detector subsystem of the AORS activatesrecording in response to a particular transient response in the user'slocal sound field, as detected by the Ambient Sound Microphones (and theresponse of the Ear Canal Microphones may be used by the Transient EventDetector subsystem).

A transient event detector to specifically detect breaking glass by anacoustic analysis of a sound field is described in U.S. Pat. No.5,917,410, which uses a multiband pressure (or voltage) envelope profileanalysis and considers relative inter-band phase.

When the Transient Event Detector subsystem in the present inventiondetects a transient with the ASMs, archival recording is activated and atime-stamp is saved separately or embedded within the audio data stream.The time stamp taken with or separately to the audio recording may beused for an audio forensic examination of the user's sound exposurehistory profile.

The AORS includes a low-memory detection system to detect whenever thecomputer data memory used for the archival recording is below aparticular threshold, and to inform the user with an auditory message.This threshold may be relative (e.g. 10%) or absolute (e.g. 10 minutesor 10 MB).

U.S. Pat. No. 2004/0268078 describes a system for detecting lowremaining computer data memory. Unlike U.S. Pat. No. 2004/0268078, theAORS does not require two separate data computer memory segments for theaudio data storage. This is advantageous as the data storage system forarchival of audio recorded with the AORS may be on a physically separatesecond device, such as a PMP, and the second device may not allow forpartitioning of storage memory (e.g. due to security features of thesecond hardware and software system).

At least one exemplary embodiment is directed to an apparatus and methodfor a self-contained Always-On headwear Recording System (AORS) that canuse as its inputs the electronic signal produced by a plurality ofmicrophone sensors mounted in one or more earphone assemblies that canbe in the left and/or right ear of an AORS User. This facilitatesmonaural or binaural recording using the output of microphone sensorsthat monitor sound at the entrance to the occluded or partly occludedear canal (ear meatus) of the user. In addition, the AORS can use as itsdata inputs the electronic signal generated by signal processingassemblies in the AORS or from a second device such as a Personal MediaPlayer (PMP) or cell-phone. The audio input data signals to the AORS areconstantly recorded to a data storage system such as a circular bufferof non-volatile RAM mounted locally on the earphone assembly. Thisfacilitates retrieval of a user's recent sound exposure (e.g. the last10 minutes) for purposes such as determining a user's sound exposurepreceding an accident (similar to a flight data recorder, or “black box”device) or facilitates the user to listen-again to a recent speechconversation. Recording of the monitored audio signal to a second audiodata storage device can be initiated manually following a user-generatedcommand, or automatically in response to a locally produced sound, suchas a user-defined verbal activation message or a transient sound such asa gunshot or a motion detecting platform that indicates the AORS User isin the vicinity of an accident. The AORS can communicate with a remoteaudio signal analysis system that undertakes speech-to-text translation,and returns a text transcript of a conversation involving the AORS user.

The present invention describes the apparatus and method for aself-contained Always-On headwear Recording System (AORS). The AORSallows a user of a voice communication system to keep a record of theirpersonal sound exposure, such as a recent conversation they had. TheAORS is constantly recording a variety of audio signals to a circularaudio buffer, therefore when the recording feature to a second audiostorage device (e.g. a cell-phone) is activated, the user already has arecent record of their sound exposure. This is particularly useful inapplications such as dictating, whereby we often decide that we wish torecord a conversation AFTER particularly interesting information hasbeen heard.

Another use of the AORS is for audio forensics to determine a soundexposure of a listening prior to an accident. The contents of thecircular buffer can be analyzed later in case of device failure.Alternatively, the AORS can detect sounds indicative of an accident oremergency, such as gunshots or car-crash sound, which can automaticallystart recording to the AORS user's local sound field without the userhaving to manually activate recording—which may be difficult for theuser under dangerous circumstances (e.g. if they suddenly come underfire).

The AORS can use as its inputs the electronic signal produced by aplurality of microphone sensors mounted in one or more earphoneassemblies that may be in the left and/or right ear of an AORS user.This allows for monaural or binaural recording using the output ofmicrophone sensors that monitor sound at the entrance to the occluded orpartly occluded ear canal (ear meatus) of the user. These microphonesensors detect sound pressure in the occluded ear canal of a user (theEar Canal Microphones—ECMs) or detect sound at the entrance to theuser's occluded ear meatus (the Ambient Sound Microphones—ASMs). Inaddition to these transducers, an ear canal receiver (ECR) can create asound pressure on the ear-drum side of the earphone device, which may beused to reproduce sound from the ASM and/or ECM, in addition to audiocontent, for instance from a Personal Media Payer or mobile phone.

In addition to, or alternatively to, the ASM and/or ECM signals, theAORS may use as its data inputs the electronic signal generated bysignal processing assemblies in the AORS or a second device such as aPersonal Media Player (PMP). The input data signals may be recordedand/or monitored by a system on a second device (such as a PMP) forarchival, forensics or other purposes. The audio input data signals tothe AORS are constantly recorded to a data storage system such as acircular buffer of non-volatile RAM mounted locally on the earphoneassembly; the AORS therefore operates as a self-contained system. Thisallows for retrieval of a user's recent sound exposure (e.g. the last 10minutes) for purposes such as determining a user's sound exposurepreceding an accident (similar to a flight data recorder, or “black box”device).

Recording of the monitored audio signal may be initiated manuallyfollowing a user-generated command or automatically in response to alocally produced sound, such as a user-defined verbal activation messageor a transient sound-detecting platform or a motion detecting platformthat indicates the AORS user is in the vicinity of an accident. The AORSmay communicate with a remote audio signal analysis system thatundertakes speech-to-text translation, and returns a text transcript ofa conversation involving the AORS user.

A Recording Status Alert System (RSAS) is included as an optional partof the AORS to inform the user and other individuals of the operatingstatus of the AORS—e.g. if it is recording ASM signals to a second datastorage device (i.e. other than the circular buffer).

An example of an embodiment of an electroacoustic assembly that theAlways On (Headwear) Recording System (AORS) may function with is givenin FIG. 1A and FIG. 1B. This shows the earphone body 10, which housesthe electro acoustic transducers (microphone 34, loudspeaker 28, andmicrophone 32) and electronic units (communication circuitry 20 (alsoreferred to herein as communication system 20, audio control datacommunication system 20 or system 20), memory 22, processing unit 24,and memory 26). The earpiece 8 forms a seal in the ear canal 1 of auser, with the outside end (at diaphragm 12) substantially flush withthe entrance 7 to the ear canal 1 (i.e. the ear meatus)—i.e. the hearingprotection device shown in this embodiment is a “completely in the ear”type, which provides passive sound attenuation of ambient soundtransmitted to the eardrum 2 of the user in the order of 20-25 dB overthe frequency range of human hearing (50-20 kHz). An ambient soundmicrophone (ASM) 34 detects sound in the front chamber 18, which may befiled with air or another substance such as a gel. An additional ASM 6may also be present on the outside of the earphone body to undertakeactive beam-forming and to provide for more omni-directional monitoringof the ambient sound field. An ear canal microphone (ECM) 32 may detectsound from the eardrum 2 side of the earpiece 8. The ASM 34 may alsodetect sound from the eardrum 2 side of the earpiece 8 via transmissiontube 30. The front diaphragm 12 serves a number of functions; it may beacoustically tuned so as to absorb certain frequencies more thanothers—and to therefore let affect the frequency response of ambientsound transmitted into chamber 18 and detected by ASM 34. This, alongwith the acoustic resonance of chamber 18, can compensate for non-linearsensitivity of the ASM 34. Furthermore, the diaphragm 12 and air-spacecan also increase the overall electroacoustic sensitivity of a signaloutput by the ASM 34 (referred to herein as an ASM signal) by working asan acoustic impedance transformer.

Holes 14 may be present in the diaphragm 12 to affect the directionalsensitivity of the ASM 34; i.e. passive beam-forming, which is aphenomenon familiar to those in the art. A number of holes may bepresent to increase the directional sensitivity of the ASM signal, forinstance in the direction of the user's mouth. In some embodiments,there are multiple ASMs in the front chamber 18, separated by dividingwalls in the chamber 18. These multiple microphones may then be used foractive beam-forming purposes in combination with external ASM(s) 6 usingdelay and summing/ differencing networks. Communication circuitry 20communicates with the other earphone device and other external devicessuch as Personal Media Players, computing devices, mobile phones, usingeither wired means (for example, communications cable 16) or wirelessmeans (e.g. Bluetooth communications assembly 4 or may be on an externalassembly such as a belt-pack or behind-the-ear assembly and may becoupled via port 5). The earphone may also communicate with a computervia miniature USB port 3. The loudspeaker 28 (also referred to herein asear canal receiver 28) is used to reproduce sound in the eardrum side ofthe earpiece 8 (also referred to herein as earphone device 8). Signalamplification and analog filtering circuitry for the loudspeaker 28 andmicrophones 32, 34 may be housed next to the respective transducer, ormay be part of the processing unit 24 (also referred to herein as DSPunit 24), along with digital-to-analog converters. Non-volatile RAMmemory 22 (also referred to herein as RAM 22) may be used to storesignals created by the DSP unit 24 or the microphones 34, 32. Programcode and pre-recorded audio may be stored in the ROM memory 26 (alsoreferred to herein as ROM 26). These individual hardware components(i.e. memory 22, 26, processing unit 24 and communication circuitry 20)may be separate or combined into a single unit 10. A battery 9 is housedin one or both of the earphone devices 8 (power may be transmitted fromone earphone device 8 to the other via communications cable 16, and maybe recharged using USB communications port 3). The tube 30 may act as apressure equalization tube, to allow for equalization of static pressurebetween the eardrum side of earpiece 8 and the outside world. There maybe more than one pressure equalization tubes, and they are designed tohave a bore sufficiently small so as to reduce the transmission ofambient sound to the eardrum 2 of the user.

FIG. 1C shows another example of an embodiment of the earphone device 8,which differs from the example in FIG. 1B with the addition of a rearchamber 38 on the eardrum side of the earphone device. This chamberserves a similar function to the previously described front chamber 18;to act as an acoustic impedance transformer to increase sensitivity ofthe ear canal microphone 32 and to improve the coupling of the ear canalreceiver 28 to the air space between the earphone device 8 and theeardrum 2. The space formed by rear chamber 38 may be filled with air oranother substance such as gel, and is protected by the diaphragm 36which may be acoustically tuned to resonate to compensate for spectralnon-linearity in the response of the transducers (loudspeaker 28, earcanal microphone 32).

FIG. 2A shows an electrical wiring overview of the Acoustic ManagementSystem. The low-battery warning system 58 informs the user of theremaining battery power, e.g. giving warnings when there is 10% and 5%remaining battery. In some embodiments of the system, the low batterywarning system 58 creates a perceptually intrusive and annoying soundwith the ear canal receiver 28, e.g. a voice message and a noise burst,when the battery power is critically low—to inform the user that theymust remove the earphone device 8 and recharge the earphone device 8(using battery charging system 56). The computer memory RAM 22 is usedfor storage of audio data and control data, and also for reproduction ofpreviously stored recordings, or music audio which may be uploaded viathe communications unit shown in FIG. 2B. The computer memory ROM 26 isa ROM unit for storing program code and pre-recorded audio for alertsetc.

The Audio and Control Data Communication system 20 shown in FIG. 2B isfor communication of the digital microprocessor 60 (also referred toherein as DSP processor 60) with other remote devices and circuitry inthe earphone device 8. The system 20 acts as an A/D converter for an ECMsignal from ECM assembly 88 and ASM signal(s) from ASM assembly 86, aswell as a D/A converter for the ECR assembly 84. The assemblies (88, 86,84) for these transducers signals include analog gain and frequencyequalization filters (which may include analog or digital circuitry, orboth). The system 20 communicates with other systems in the earphonedevice 8 such as local audio storage 82 (e.g. a RAM computer memory) aswell as external devices such as a remote audio storage 80 (e.g., a PMP)(for both retrieval of audio content and for use as a storage system forrecorded audio), and also other signals such as audio signals frommobile phones 72, other earphone devices 74 worn by the same user orother earphone devices 75 worn by different users. System 20 may alsocommunicate with a remote data processing system 76 (e.g., forspeech-to-text, language translation). The means of communication of theaudio or control data signals may be by wired or wireless means. Theoptional visual display 42 gives the user information about theoperating status of the earphone device 8, e.g. remaining memory,battery, recording status, as well as informing other people of theoperating status of the earphone device 8—e.g. if the earphone deviceuser can hear their ambient sound field, or if they are busy with aphone call. The visual display may be combined with the user controlinterface 40, or may be separate. The control interface may use, forexample, a touch-sensitive screen system or separate buttons, and may bemounted on a user-wearing jewelry such as a bracelet, that can also beused for marketing purposes such as to advertise a brand name ornon-commercial campaign.

FIG. 3A depicts a functional overview of the Always On Recording system(AORS)—which is described in FIG. 3B—in relation to various audio andcontrol data communication channels through the communications assemblyshown in FIG. 2B. The AORS is always recording one or more audio signalsto a circular data buffer (such as the non-volatile RAM 22), so when thepermanent recording is activated either automatically (see FIG. 3E) ormanually 96 (see FIG. 3B) with manual activation unit 62, the contentsof this buffer (which may be a history of the last 10 minutes—or anytime duration determined by the user or determined automatically) isalso recorded. The audio channels that are recorded are selected by thesystem described in FIG. 3C. The recording status alert system shown inFIG. 3D informs the user and other individuals the user may becommunicating with (e.g. with a cell phone) that the audio is beingpermanently recorded, e.g. with an auditory message or repeating soundcue such as a periodic beep.

FIG. 3B gives a functional overview of the Always On Recording System.The operating mode selected 94 by the user with user input system 98(which may be configured using a computer) selects which channels willbe continuously recorded to the circular buffer 100. When the “recordingactivation module” described in FIG. 3E selects the “long-term” mode,then the audio data on audio input signal bus 90 and the contents of thecircular buffer 100 are recorded to a data storage device with a largermemory capacity than the circular buffer 100. This is affected by switch102, as decided by decision logic 104, switch-opening circuitry 110 andswitch-closing circuitry 108 (which enables the audio to be recorded tothe larger memory device). The selected audio signals may first beprocessed by a first audio encoder-1 92. This may reduce the data-rateusing lossy or loss-less audio signal encoding algorithms, e.g. using aperceptual encoder or Hoffman encoding. The signal recorded in circularbuffer 100 may therefore be an encoded signal representing manymultiplexed audio channels. The buffer may also record non-audio data,such as a time-stamp generated by time stamp unit 91 that may be updatedon a sample-by-sample or intermittent basis. The circular buffer 100 maybe made using non-volatile computer memory, so that in the event of anaccident, an audio record of the audio signals exposed to the user, or(for example) the audio signals detected by the ASMs, can be analyzedsimilar to a “black box” in-flight recorder used in airplanes. When theswitch 102 is closed, the audio signal may be further encoded or decodedusing Audio Signal CODEC-2 106, before being recorded to either or botha local audio data memory 114 or a remote audio data memory 116. A lowremaining-memory warning system 118 monitors the remaining memory of theaudio data memory 114 and/or 116 and issues auditory, visual, or tactilewarnings (or a combination of the above) with user alert system 120 tothe user when the remaining-memory level becomes low (e.g. a 10, 5 and 1minutes warning). The recording status alert system shown in FIG. 3Dinforms the user and other individuals the user may be communicatingwith (e.g. with a cell phone) that the audio is being permanentlyrecorded, e.g. with an auditory message or repeating sound cue such as aperiodic audio beep.

FIG. 3C shows a Functional overview of an Always On Recording Systemchannel-record selector system. The system selects which audio signalsare continuously recorded using the AORS 152, and also which signals aremonitored by the user with sound reproduction means 154 (e.g. the EarCanal Receiver—ECR). Examples of such audio signals are: the left 136and right 138 Ear Canal Microphones (ECMs), via ECM signal conditioningcircuitry including gain 140 and filtering (illustrated as equalizer(EQ) filter 142) (which may use either or both analog and digitalfiltering means); the left 124 and right 126 Ambient Sound Microphones(with signal conditioning circuitry (i.e., gain 128 and EQ filter 130);and audio content 143 (audio signals from a mobile phone 122; auditorywarning signals 134 created by either or both the earphone device (e.g.a low-battery signal) or another device; and audio from a PMP 132 (whichmay be a mono or stereo signal)). The signals that are monitored withsound reproduction means 154 are selected and mixed using the AGC unit156, which may be configured either manually 144 or automatically 146.The signal selector 150 determines which signals are recorded with theAORS 152 using either manual 144 or automatic 146 configuration means.

FIG. 3D gives a Functional overview of the Recording Status AlertSystem. This system informs the headphone device user and any otherindividuals whom the user may be communicating with (e.g. with a mobilephone) that the AORS is recording particular audio signals to apermanent audio data storage device. When the AORS is activated (seeFIG. 3E) to continuously record the contents of the circular buffer to asecond data storage device (e.g. a PMP—as shown in FIG. 3B) with a startrecording signal, or to stop this recording, the system in FIG. 3E takesthe stop/start recording command 158 and if this is a “stop” signal(determined by unit 166) then a stop signal is generated using apparatus170 (e.g. a voice message 168 or a non-speech audio signal 172). If a“start” message is generated, then a different audio signal may begenerated using system 178 (e.g. a voice message 174 or a non-speechaudio signal 176). If a particular operating mode is selected 164 (suchas for a periodic warning signal 180), then a repeating auditory messagemay be reproduced 186 (with delay 187), which again may be a voicemessage 182 or a non-speech audio signal 184. The particular auditorymessage is communicated via communications system 20 to the ear canalreceiver (loudspeaker) assembly 84 of the user, or to another individualwho the user may be talking with via mobile phone (for example remoteindividual 70), and this message may also be recorded by the AORS.Besides an audio message, the Recording Status Alert System may alsogenerate a non-sound message, such as a visual indicator light mountedon the earphone device (for example on visual display 185), to informother individuals that the AORS is recording 185.

FIG. 3E depicts a functional overview of the Recording Activation systemfor the AORS. This system starts recording 200 of the circular buffer toa second data storage device (see FIG. 3B). The system may be triggeredmanually 198 by the user, or manually by a remote individual (i.e.,externally triggered 190) via the control data communication system 20.Alternatively, the AORS recording may be triggered automatically bymonitoring the audio signals 188 selected for recording (see FIG. 3C) orother signals, such as the ambient or ear canal microphones. One exampleof an automatic activations system is the signature sound ID system 192(SSIDS). This detects certain speech or non-speech sounds, which may bepredefined or defined by the user. Such sounds could be a certain numberof hand-claps, a gun-shot, an explosion, a particular whistle, or akey-word or words such as “record”. Another activation method is bydetecting transient sounds 194 which may be indicative of an accident.Accident detection may be determined by accident detector module 196.

At least one exemplary embodiment is directed to a self-containedAlways-On Recording System (AORS) which operates like aviation “flightrecorders” by storing a recent history of electronic sound signalspresented to a user with an earphone device whilst simultaneouslyrecording sound in the user's local ambient sound field using an AmbientSound Microphone at the entrance to the user's fully or partiallyoccluded ear canal, and simultaneously recording sound in the user'soccluded or partially occluded ear canal using an Ear Canal Microphone.

The AORS comprises: an assembly to monitor the acoustic field in auser's immediate environment using an Ambient Sound Microphone (ASM) tomonitor sound at the entrance to one or both occluded ear canals; asignal processing circuit to amplify the signal from the ASM and toequalize for the frequency sensitivity of the microphone; an assembly tomonitor the acoustic field in an occluded ear canal comprising amicrophone mounted in an earpiece that forms an acoustic seal of one orboth ear canals of a user (this is the Ear Canal Microphone; ECM); asignal processing circuit to amplify the signal from the ECM and toequalize for the frequency sensitivity of the ECM; an optional signalprocessing circuit to amplify and process an audio content input signal(e.g. from a Personal Media Player, cell phone, orautomatically-generated auditory warning signal); an audio signal routerand switching matrix to select which of three sets of audio signalsdiscussed above is to be recorded using the AORS; a user AORSconfiguration system (e.g. a physical switch on the earphone or asoftware-based selection system on a computer) that controls the audiosignal router and switching matrix; an optional audio signalmultiplexing and lossy or lossless data-rate reduction system forprocessing the audio signals from the audio signal router and switchingmatrix; a data storage device (e.g. non-volatile RAM) to act as acircular buffer for constantly recording the output signal of theoptional data-rate reduction system, or the audio signals from the audiosignal router and matrix, into a circular computer memory data buffer,comprising non-volatile RAM mounted either within the earphone assemblyor on a second data-storage device (e.g. a PMP); an AORSrecord-activation system to activate recording of the contents of thecircular buffer to a second audio signal data storage device, such as ahard-drive on a PMP; an optional second audio signal multiplexing andlossy or lossless data-rate reduction system for processing the audiosignals from the circular buffer in before transmission to a secondaudio signal data storage device, such as a hard-drive on a PMP; anoptional time-stamp audio index system for embedding a time-coded indexinto the audio signal data transmitted to the second audio signal datastorage device; a system for transmitting either the audio signal storedin the circular buffer or the reduced data-rate signal to a second datastorage device, such as with a wireless transmitter or physical wire; anearpiece that forms a seal in the ear canal of the AORS user whichhouses the above ASM, ECM, ECR and electronic components; an optionalpressure equalization tube to equalize the pressure on the ear-drum sideof the earpiece relative to the ambient pressure.

At least one future exemplary embodiment can further include a diaphragmto cover the ASM to provide one, all, or a combination of the followingcapabilities: an acoustic diaphragm covering the ASM with holes atspecific locations to provide passive beam-forming. The holes may becovered by a different material than the diaphragm material; such as agrill, a different material, an air space (i.e. no covering); anacoustic diaphragm covering the ASM that is tuned to resonate atpre-determined frequencies. The tuning of the diaphragm is such thatdifferent frequencies are transmitted through the diaphragm (and intothe space behind, and thus detected by the ASM) with differentattenuation losses; i.e. the Frequency-Dependant Noise Reduction Ratingof the diaphragm is different for different frequencies; an acousticdiaphragm covering the ASM that is illuminated either behind thediaphragm (i.e. on the ear-drum side) or outside using LEDs to displaythe current operating status of the AORS; for instance, to show it ispowered and active, to inform local individuals that the AORS user iscurrently recording their local ambient sound field, to inform localindividuals that the AORS user is currently monitoring audio content anddoes not wish to be disturbed; and an acoustic diaphragm covering theASM that can be used for marketing purposes to display a particularproduct brand, logo, or non-commercial public awareness campaign such asa “safe hearing” campaign.

Another exemplary embodiment of the invention can include a recordingactivation system to automatically start recording of the circularbuffer to a second data storage device. The recording activation systemcomprises one, all, or a combination of the following; a Signature SoundID system which continually monitors audio signals for particular speechkeywords, particular sounds such as hand-claps, gun-shots or whistles,or general sounds such as a particular person's voice or a sound sourcewhich is approaching. The monitored audio may include one or acombination of the following: an ambient sound microphone signal formone or both earphone devices of the user; an ear canal microphone signalform one or both earphone devices of the user; an audio content from aremote individual (e.g. from a cell-phone or walkie-talkie); an audiocontent from a PMP such as a portable DVD player or computing device; atransient event detector that monitors audio signals from a transientsound event indicative of an accident. Monitored audio signals arelisted a-d above; an accident detector system that analyzes motion ofthe user using miniature accelerometers housed within the earpieceassembly or housed elsewhere on the body of the user, and initiatesrecording of the circular buffer to a second data storage device whenthe accelerometers indicate a fall or that the user has been involved ina collision; an externally triggered activation system whereby recordingof the circular buffer to a second data storage device can be initiatedby a remote second individual with a wired or wireless communicationmeans; a means to trigger recording of the circular buffer to a seconddata storage device whenever improper functioning of the earphone deviceis detected. Examples of improper functioning include: poor-fitting ofthe earpiece, electronics failure.

At least one further exemplary embodiment additionally includes aRecording Status Alert System (RSAS). The RSAS informs the user andother individuals whether the AORS has currently initiated recording ofthe circular buffer to a second data storage device. The RSAS systemcomprises the following: a decision unit to determine if the AORS isoperating in a mode whereby the circular buffer is being recorded to asecond data storage device. If so; the AORS is in “recording mode”;otherwise the AORS is in “non-recording mode”; a system to generate anaudio signal when the AORS is switched from a “non-recording mode” to a“recording mode”. This signal may be a pre-recorded speech message, apre-recorded non-speech message, or may use an algorithm to generate amessage; a system to generate an audio signal when the AORS is switchedfrom a “recording mode” to a “non-recording mode”. This signal may be apre-recorded speech message, a pre-recorded non-speech message, or mayuse an algorithm to generate a message; an optional system to generatean audio signal when the AORS is in “recording mode” at repeatingintervals; a communication system to transmit the audio signals above toone, all, or a combination of the following systems: the ear-canalreceiver assembly of the AORS user in one or both earphone devices; aremote individual who the AORS user may be communicating with, such asvia a mobile-phone or a walkie-talkie radio; the second data storagedevice of the AORS; an optional visual display system to inform the userof the status of the AORS. This may be a remote control unit, forinstance worn on the wrist of the user. It may contain information aboutremaining battery life and remaining memory of the second data storagedevice, and the particular operating mode; an optional visual displaysystem to inform other individuals in the vicinity of the user of theparticular operating mode of the AORS; for instance, with LEDs mountedon the exterior of the earphone device which indicate if the “recordingmode” or “non-recording mode” is currently operational.

At least one further exemplary embodiment includes a remote audioforensics analysis system for analyzing either the contents of thecircular buffer or the data stored on the second data storage device.This remote audio forensics system includes all, either or a combinationof the following functionality; an audio signal data communicationsystem for transmitting the contents of the circular buffer to a remoteserver for analysis of the audio signal; an audio signal datacommunication system for transmitting the contents of the second datastorage device (e.g. PMP or mobile phone) to a remote server foranalysis of the audio signal; a data communication system fortransmitting the analysis of the audio data back to the AORS user, e.g.via email, SMS text, or as a computer-generated speech text; aspeech-to-text analysis system on the remote server; a languagetranslation system to translate text from one language to another; atext-to-speech translation system to translate text into speech fortransmission back to the AORS user; a text-based acoustic event loggingsystem whereby the time-stamped audio data communicated to the server)is analyzed for pre-determined events such as transient sounds, and alog of the sound exposure of the user is made and optionallycommunicated back to the user, e.g. with an SMS or email; a system whichanalyzes the audio data to determine if the AORS user has been involvedin an accident, e.g. if a car-crash or gun-fire sound is detected. Theforensics analysis system then automatically informs another individualsuch as an emergency response team that the particular AORS user hasbeen involved in a potential accident, and optionally sends this secondparty an audio record of the data that was analyzed.

In another exemplary embodiment, a Low-Memory Warning System detects ifcomputer memory used to store audio signals is about to be exhausted andinforms the user to take action. This system includes: a system tocalculate the relative remaining memory in a second data storage devicesuch as a hard-drive on a PMP or cell-phone, RAM computer memory in theearphone device or on a PMP. The first input to this remaining memorycalculation system is the total memory of the second data storage deviceand the second input is the current total used memory of the second datastorage device. The remaining memory calculation system returns a valueeither as a percentage or as a time value corresponding to the estimatedtotal remaining record time (e.g. expressed in minutes); alternative tothe relative remaining memory system is a system that calculates theremaining memory only in absolute terms (e.g. in MB) and returns a valuerelated to this (e.g. by analyzing a data recording rate, an estimate ofthe remaining record time can be calculated); a series of electronicmagnitude comparators (at least one) that compares the result of theremaining memory calculation system to a series of constants and returnsa series of priority messages (the number of different possible messagesis equal to the number of comparators). The numerical constants used bythe comparators are related to remaining memory boundaries such as “10%remaining”, “5% remaining” and “less than 1% remaining”, and thiscomparator system works like a low battery-level warning system; anauditory user warning messaging system to inform the user when aremaining audio memory level is below a predefined value, this may be anauditory message automatically generated or reproduced from an audiosignal generation circuit within the earphone assembly, or transmittedfrom a second device (e.g. PMP), the message may be in a number offorms, for instance, a verbal message that informs the user about theneed to cease using the AORS, or a repeating very intrusive and annoyingauditory message which forces the user to cease wearing the earphones;an optional visual warning messaging system to inform the user whenremaining audio memory level is below a predefined value; and anoptional tactile warning messaging system (such as a vibration systemattached to the user's wrist) to inform the user when remaining audiomemory level is below a predefined value.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all modifications, equivalent structures and functions of therelevant exemplary embodiments. Thus, the description of the inventionis merely exemplary in nature and, thus, variations that do not departfrom the gist of the invention are intended to be within the scope ofthe exemplary embodiments of the present invention. Such variations arenot to be regarded as a departure from the spirit and scope of thepresent invention.

What is claimed is:
 1. An Always-On Recording System (AORS) comprising:a monitoring assembly mounted on a mobile phone, the monitoring assemblyincluding an ambient sound microphone (ASM) to monitor an ambientacoustic field proximate to the mobile phone, the ASM producing an ASMsignal responsive to the ambient acoustic field; a data storage deviceconfigured to act as a circular buffer for continually storing the ASMsignal; a further data storage device coupled to the data storagedevice; and a record-activation system including software configured toactivate the further data storage device to record a content of the datastorage device.
 2. The system according to claim 1, where therecord-activation system is configured to activate the further datastorage device responsive to detection of at least one of a speechsound, a non-speech sound or a transient sound in the content of thedata storage device.
 3. The system according to claim 1, where theambient sound microphone includes a plurality of ambient soundmicrophones.
 4. The system according to claim 1, the system furthercomprising: a signal processing system configured to at least one ofmultiplex output signals from the circular buffer or encode the outputsignals to reduce a data rate before transmission of the output signalsto the further data storage device.
 5. The system according to claim 1,where the system is further configured to receive one or more of anaudio content signal from the mobile phone or at least one further audiosignal from an other device.
 6. The system according to claim 5, wherethe other device includes at least one of an earphone device worn by auser of the mobile phone, a further earphone device worn by a differentuser, a media player or a computing device.
 7. The system according toclaim 5, the system further comprising: a signal processing circuitconfigured to process at least one of the ASM signal, the audio contentsignal or the at least one further audio signal; and a signal router andswitching matrix to select which signals among the ASM signal, the audiocontent signal and the at least one further audio signal are recordedinto the data storage device.
 8. The system according to claim 7, thesystem further comprising: a user AORS configuration system configuredto control the signal router and switching matrix.
 9. The systemaccording to claim 7, the system further comprising: a signal processingsystem configured to at least one of multiplex output signals from thesignal router and switching matrix or encode the output signals from thesignal router and switching matrix to reduce a data rate.
 10. The systemaccording to claim 1, the system further comprising: a time-stamp audioindex system configured to embed a time-coded index into the contenttransmitted to the further data storage device.
 11. The system accordingto claim 1, the system further comprising: a diaphragm to cover the ASM.12. The system according to claim 11, where the diaphragm is an acousticdiaphragm covering the ASM with holes at specific locations configuredto provide passive beam-forming.
 13. The system according to claim 11,where the diaphragm is tuned to resonate at pre-determined frequencies.14. The system according to claim 1, the system further comprising: aRecording Status Alert System (RSAS) configured to provide an indicationwhen the further data storage device records the content of the datastorage device.
 15. The system according to claim 14, where the RSAScomprises: a decision unit to determine whether the content of thecircular buffer is being recorded to the further data storage device; afirst system to generate an audio signal when the further data storagedevice is activated to store the content of the data storage device; anda second system to generate a further audio signal when the further datastorage device is activated to stop storing the content of the datastorage device.
 16. The system according to claim 15, where the firstsystem generates the audio signal at repeating intervals while thefurther data storage device stores the content; and the RSAS transmitsat least one of the audio signal or the further audio signal to at leastone of the mobile phone, a remote location, the further data storagedevice or a visual display system.
 17. The system according to claim 1,the system further comprising: a remote audio forensics analysis systemconfigured to analyze either the content of the circular buffer or datastored on the further data storage device.
 18. The system according toclaim 17, where the remote audio forensics analysis system includes acommunication system configured to transmit at least one of the contentof the circular buffer or the data of the further data storage device toa remote server for analysis of the ASM signal.
 19. The system accordingto claim 18, where the remote audio forensics analysis system isconfigured to receive results of the analysis from the remote server.20. The system according to claim 19, the system further including: atext-to-speech translation system to translate the received results ofthe analysis from the remote server into speech.
 21. The systemaccording to claim 20, the system further comprising: a text-basedacoustic event logging system for detecting and logging at least oneevent based on the received results of the analysis.
 22. The systemaccording to claim 1, the system further comprising: an analysis systemwhich analyzes the ASM signal to determine if a user of the AORS hasbeen involved in an accident.
 23. The system according to claim 22,where when the accident is determined the system automatically transmitsan indication to a remote location that the user has been involved inthe accident.
 24. The system according to claim 1, system furthercomprising: a low-memory warning system configured to provide anindication when a remaining memory level of the further data storagedevice is less than a predetermined amount.
 25. The system according toclaim 1, the system further comprising: a signal processing circuitconfigured to at least one of amplify the ASM signal or equalize afrequency sensitivity of the ASM signal.